JPS6194313A - Manufacture of resin mold type transformer - Google Patents

Abstract

PURPOSE:To enable using a non-cut type wound core by impregnating a synthetic resin after a winding is wound on the external side of a resin permeation prevention layer provided by electrostatic powder coating on the surface of an insulating tape wound on the whole external surface of the wound core of an amorphous magnetic alloy thin film belt. CONSTITUTION:An amorphous magnetic alloy thin film belt 2 is continuously wound and a rectangular type no cut iron core 1 the whole external surface of which is sprayed with a rust proofing agent 3 for anticorrosion treatment is made. Then, an insulating tape 4 which has thermal resistance and buffer effect is wound on the rust proofing agent 3 with 1/4-1/2 ratio duplication according to the insulation strength required by a transformer, powder 5 is adhered on the tape by an electrostatic powder coating equipment and heated to make a hard and minute resin permeation prevention layer. Then, the both legs of the iron core 1 are wound with windings 11 and the whole body is molded with such as an epoxy system resin. In this way, using of the non-cut type iron core is made possible and iron loss is also reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a resin mold type transformer using an uncut wound core made of an amorphous magnetic alloy ribbon.

[Technical background of the invention and its problems]

Recently, the use of amorphous magnetic alloy ribbon as the core material for transformer cores has been considered. This amorphous magnetic alloy ribbon is manufactured by ultra-quenching a molten magnetic alloy, and has extremely low iron loss and excellent magnetic properties, making it suitable as an iron core material.

However, although the amorphous magnetic alloy ribbon has low loss, it is thin and brittle, making it difficult to process and causing brittleness after annealing. For this reason, when constructing a transformer core from an amorphous magnetic alloy ribbon, a structure is adopted in which the core has an uncut wound core structure and the windings are directly wound around this wound core.

On the other hand, resin molded transformers have recently been increasingly used as transformers installed indoors. This type of transformer is constructed by combining windings impregnated with synthetic resin under vacuum pressure and an iron core.
It has an insulating strength that can withstand a potential gradient of around 2 kV/m, and is characterized by improved flame retardancy, improved maintenance, and improved heat resistance. It is conceivable to take advantage of this feature to construct a resin molded transformer made of amorphous magnetic alloy ribbon, but it is difficult to incorporate the wound core into the molded winding with an uncut type, and one-turn/cut If you have to cut it into a C-shaped or C-cut shape, which requires cutting, or if you have to deal with the amorphous magnetic alloy ribbon, which has become brittle due to annealing, when incorporating it into the winding. This may cause damage to the wound core. On the other hand, there are also configurations such as resin molded transformers in which the wound core and winding are integrally molded in resin, but amorphous magnetic alloy ribbons are highly sensitive to stress and have a property that their magnetic properties greatly deteriorate when subjected to external force. Since the shrinkage force during resin curing is
jf! : It must be ensured that it does not affect the constituent amorphous magnetic alloy ribbon.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and provides a method for manufacturing a resin molded transformer equipped with an uncut wound core made of an amorphous magnetic alloy ribbon without reducing the magnetic properties of the ribbon. The purpose is to

[Summary of the invention]

The method for manufacturing a resin molded transformer of the present invention includes forming an insulating layer by winding an insulating tape around the outer surface of a wound iron core formed by winding an amorphous magnetic alloy ribbon, and forming an insulating layer on the outer surface of the insulating layer. A resin permeation prevention layer is formed on top by electrostatic powder coating, a winding wire is wound on the outside of the layer, and then the winding wire is impregnated with a synthetic resin.

[Embodiments of the invention]

Embodiments of the present invention illustrated in the drawings will be described below.

1 to 5 show each step in an embodiment of the manufacturing method of the present invention, and FIG. 6 is a sectional view showing the surface of the wound core.

First, as shown in FIG. 2, an amorphous magnetic alloy ribbon 2 is continuously wound to form a rectangular shape.

A wound core 1 having a shape of 1 is formed. The entire outer surface of the wound core 1 is coated with a rust preventive agent 3 such as A manufactured by Norstan Instrument Co.
Spray XXADRY (product name) to prevent rust.

Next, as shown in FIG. 3, an insulating tape 4 is wrapped over the entire surface of the rust preventive agent 3 attached to the outer surface of the wound core 1 to form an insulating layer. The insulating tape 4 is made of an insulating material that has heat resistance and a buffering effect in accordance with the insulation strength required for the transformer. For example, if the transformer has an insulation strength of Class F or higher, glass fiber tape is used. In addition, polyester tape, Kabuton tape, etc. can also be used. In addition, the insulating layer is formed by overlapping and winding insulating chips F4 at a ratio of 1/4 to IA to improve powder adhesion in electrostatic powder coating, which will be described later, and to prevent powder from penetrating into the wound core. to prevent

Next, as shown in FIG. 1, electrostatic powder coating is applied to the wound core 1 having an insulating layer of insulating tape 4 using an electrostatic powder coating device. In other words, in the figure, 6 is the device body, and 7 is the main body of the device. The high voltage electrode 9 connected to the high voltage generator #8 is a porous plate. The wound core 1 is grounded and arranged on the upper part of the device main body 6. Then, air 1o is supplied from the lower part of the device main body 6, ionized by the high-voltage electrode 7, and passed through the porous plate 9, thereby suspending the powder 5 on the porous plate 9 and electrostatically charging the powder 5. let The charged powder 5 becomes atomized above the device body 6, is electrostatically attracted to the grounded core 1, and adheres to the entire surface of the insulating layer of the core 1. Thereafter, the powder 5 is heated in a heating furnace to melt and harden and adhere to the insulating layer. As a result, as shown in FIG. 4, the powder 5 covers the entire surface of the insulating layer to form a hard and dense resin penetration prevention layer.

Next, as shown in FIG.
Wind 1'Jt. In this case, a bobbin is fitted onto the wound core in the same manner as in the winding process for a normal uncut wound core, the bobbin is rotated, and one winding wire is wound around the bobbin.

Next, this winding wire I is impregnated with a resin. The resin impregnation treatment involves placing the winding 11 together with the wound core 1 in a resin bath, impregnating the winding 1 with a synthetic resin such as epoxy resin under vacuum pressure, and then heating the synthetic resin impregnated into the winding 11. This is done by hardening.

Here, since a hard and dense resin permeation prevention layer is formed on the outer surface of the wound core 1 via an insulating layer, the synthetic resin does not permeate during the resin impregnation process. Wound core 1 for io
Since the curing and shrinkage force of the synthetic resin does not act on the amorphous magnetic alloy ribbon 2 constituting the structure, there is no deterioration in magnetic properties.

In addition, the electrostatic powder coating that constitutes the resin penetration prevention layer is applied to the wound core 1.
When the amorphous magnetic alloy ribbon 2 was irregular, the wound iron core 1
Even if the cross section of is stepped, the insulation Te = 7' (
Since it is applied to the smooth outer surface of the insulating layer formed by winding the insulating layer, it can be applied easily and uniformly. Further, since the insulating layer has a buffering effect, the external force applied to the wound core 1 is absorbed by the buffering effect. Therefore, a protective layer is formed for the wound core 1 by combining an insulating layer with a buffering effect and a resin permeation prevention layer made of strong electrostatic coating powder 5, and the force applied to the amorphous magnetic alloy ribbon 2 from the outside is Amorphous magnetic alloy ribbon 2
It is possible to prevent distortion from occurring. Therefore, it is possible to prevent the magnetic properties of the amorphous magnetic alloy ribbon 2 from deteriorating due to external forces applied to the wound core 1 during the manufacturing process of the transformer or during handling of the transformer. Furthermore, since the rust preventive agent 3 is applied to the wound core 1 and sealed with the electrostatic coating powder 5, the rust preventive effect of the rust preventive agent 3 is maintained over a long period of time, and the amorphous magnetic alloy ribbon is 2
Can prevent rusting.

Table 1 shows the results of measuring the iron loss of the wound core in a transformer manufactured by the manufacturing method of the present invention and the iron loss of the wound core in a transformer manufactured by another manufacturing method. In either case, the material of the wound core is METAGLAS 2602 manufactured by Allied Corporation in the United States, which is a typical amorphous magnetic alloy ribbon.
S-2 was used.

Table 1 In the example of the present invention, the surface of the wound core is covered with an insulating layer made of glass tape and a resin permeation prevention layer made of electrostatic powder coating, so the wound core is not impregnated with resin even after resin impregnation treatment. ,
The core loss of the wound core was the same as the core loss of the amorphous magnetic alloy ribbon. That is, the iron loss increase rate with respect to the material in the wound core was 0%. On the other hand, when an insulating layer is not provided and only a stop layer is provided during resin penetration by electrostatic powder coating, the characteristics are not constant from 0 to 1 (l), and therefore, the characteristics are not constant due to the provision of an insulating layer. It can be seen that the effect is large.Furthermore, if the wound core is not coated, the resin will be impregnated into the wound core during the resin impregnation treatment, and as a result, the iron loss of the wound core will be very large. The increase rate of iron loss relative to the original iron loss of the crystalline magnetic alloy ribbon was about 200 to 300 inches.

〔Effect of the invention〕

As explained above, according to the method of manufacturing a resin molded transformer of the present invention, it is possible to use an uncut wound core made of an amorphous magnetic alloy ribbon, and to prevent the wound core from being impregnated with resin. It is possible to obtain a resin molded transformer that can exhibit the excellent magnetic properties of an amorphous magnetic alloy ribbon.

[Brief explanation of drawings]

1 to 5 are explanatory diagrams showing manufacturing steps in one embodiment of the manufacturing method of the present invention, and FIG. 6 is a sectional view showing an enlarged surface portion of the wound core. 1... Wound iron core, 2... Amorphous magnetic alloy ribbon, 3...
- Rust preventive agent, 4... Insulating tape, 5... Powder, 11.
... Winding O Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (2)

[Claims] (1) A step of winding an amorphous magnetic alloy ribbon to form a wound core, a step of winding an insulating tape around the entire outer surface of this wound core to form an insulating layer, and a step of forming an insulating layer on the outer surface of this insulating layer. The method comprises the steps of: forming a resin permeation prevention layer on the resin permeation prevention layer by electrostatic powder coating; winding a winding wire on the outside of the resin permeation prevention layer; and impregnating the winding wire with a synthetic resin. A method for manufacturing a resin molded transformer, characterized by: (2) The method for manufacturing a resin molded transformer according to claim 1, wherein the outer surface of the wound core is subjected to rust prevention treatment and an insulating tape is wound thereon to form an insulating layer.